awesome thanks for that it's always interesting to see what mr weagle has to say, particularly on this extremely hot topic!Got DW to take a minute or two out of his schedule to answer a few questions about the bike. Not many, but I can't afford his hourly rate to answer more questions.
DW Link to Turner for 09
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- .iron horse is dead .long live iron horse anal bum covers armchair engineers be or not to be chuck weagle dw-link ethnocentric americanism fapping flexy links gripe needs a nap i is ungineer jcl lubes stanchions linky squeeze pinky salad tossing by jcl sam hill=turner sticky keyboard turner wannabe sunday you know you want!
http://www.pinkbike.com/news/DW-link-Turner-bikes-2008.html I am drooling over the new DHR!
DW will finally has someone to properly execute his design, stoked for DW and Dave.
I guess I'll start saving my pennies now.
DW will finally has someone to properly execute his design, stoked for DW and Dave.
I guess I'll start saving my pennies now.
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I don't know if i'm the only one to say it, but i'll say it again, the DHR looks fan-****ing-tastic! The rendering makes it look a little complex/mashed up, but i'm sure the real thing with a nice racey build around it will look killer! It's my dream bike for sure...
Does anyone know if the geometry of the new DHR is the same or close to that of the Sunday? I ask because, although the DW-Link no doubt works, the thing that set the Sunday apart from me was the geometry and the body position it put you in. I'd happily take a bike which wasn't quite as good in the CADworkspivotfluiddynamicsratecurvewhatsitsname if I can work with the angles better.
Wow, from a rendering?
with the uber-success of the Sunday I can't imagine why they wouldn't all but copy those geo numbers.
From this;
"All in all though, link spacing is not something that is really a focus. I'm looking more at absolute suspension performance and structural performance."Got DW to take a minute or two out of his schedule to answer a few questions about the bike. Not many, but I can't afford his hourly rate to answer more questions.
Say what now? Link spacing not a focus? Structural performance? Form or Function Dave - I've got to guess this design is compromised structurally from the need for it to LOOK like a Turner. Carrot's not withstanding, pivots close together = less stiff in torsion (though I guess the come-back is 'less stiff, but still above a required threshold')
It mostly comes from trust i have in Dave's previous frames, that i will like how this frame looks in person. I like the industrial/workhorse style...Wow, from a rendering?
I am surprised by how much everyone thinks the DHR is a ugly Beast... i agree the rendering isn't super appealing but use a little imagination!!
To ward of the bad vibes of that crazy smily, here's old mate
I think you missed the point... he didn't focus solely on link spacing, instead absolute structural performance, ie, by putting material where it needs to be and using large diameter pivots = stiff enough chassis for DH racing!
I was thinking about that too, but heres what i came up with.
If you look at quite a few VPP bikes, the linkages are further apart, which in theory is like holding the swingarm at the widest point, thereby making things nice and stiff.
But the single pivot DHR has everything in one spot, and its still stiff.
So.
I figure, wide links does not necessarily make a stiff bike. Its how they are done thats key. And again, not to repeat myself, but dave and dave are smart little buggers, and know a think or two about building bikes, so I am able to give them the benefit of the doubt, at least until proven wrong in the real world.
If you look at quite a few VPP bikes, the linkages are further apart, which in theory is like holding the swingarm at the widest point, thereby making things nice and stiff.
But the single pivot DHR has everything in one spot, and its still stiff.
So.
I figure, wide links does not necessarily make a stiff bike. Its how they are done thats key. And again, not to repeat myself, but dave and dave are smart little buggers, and know a think or two about building bikes, so I am able to give them the benefit of the doubt, at least until proven wrong in the real world.
Possibly I missed the point. Possibly its smoke and mirrors to obscure a compromised design.
Most likely it doesn't matter that much and the bike will rock.
All else being equal, wider spacing always means stiffer. Always.
The sizing of pivots/bearings/shafts etc is about wear/serviceability, crush/shear stresses, look ('oversize' this and that = extra burly in the minds of huxxors) more than torsional stiffness of the chassis.
They know a lot / benefit of the doubt - damn right. And the real world is where it matters of course, I'm just being a pedantic e-nerd.
I understand completely, and I agree about the stiffness bit. But, look at the current DHR. Everything is relatively compact, yet it makes for a nice stiff bike. So, I guess really, we'll see when it comes out.
That was cool. Nice work. So good to see two great MTB names come together and take the whole thing onto another level. Stoke-a-mundoGot DW to take a minute or two out of his schedule to answer a few questions about the bike. Not many, but I can't afford his hourly rate to answer more questions.
10 pts to turner for that rear brake IS/ post mount combo.
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For Christs sake can we get rid of that "Official Ironhorse/DW Tech and Tuning Section" thread, it is so passe. We need an Official Turner/DW Tech and Tuning Section so I can inter-tune my new Inter-bike!
Seriously though, if the production model looks at all like the picture, that bike is going to ride like it is a feather weight. Center of mass could not be any more low and centered than that!
Seriously though, if the production model looks at all like the picture, that bike is going to ride like it is a feather weight. Center of mass could not be any more low and centered than that!
You're actually right Jeff, the pivots themselves and their integration into the frame is what matters most to how 'stiff' a rear end is. Rollers; Ball bearings; the size; using an axle for the rollers?; etc. There's no such thing as 'all things equal' when comparing pivot designs. Single pivots can put more weight (bigger bearings, use hardened shafts, etc) in one pivot, whereas VPPesque frames must distribute that weight over several pivots. Obviously the structure of the arms play a factor, but we're comparing force distributed over one beef axel vs 4 or 5 weaker ones.
Take for instance a Nicolai M-Pire. Compare to a Cortina 8......
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Ride like a feather weight? It's going to be a feather weight!
From Pinkbike interview with Dave Weagle
Lol - I think that thead will be around as long as people are ripping on their 05 - 09 dw-link Sundays...
As for a "Turner / dw-link Tech. & Tuning Section" - WAY ahead of you man...
:biggrin:
...just need to get a hold of dw one of these days when he's NOT busy... which is nearly impossible.
True, but longer links are always flexier. Always.
Links themselves should never be flexing. The pivots in either end are what flex. A longer link can sometimes offer more mechanical advantage to torsionally load the bearing in the end.
That said, the link layout on that DHR is simply retarded from a structural standpoint. I should buy stock in whoever is supplying pivot/linkage kits for that thing.
Can you show me the links on the bikes you designed and successfully brought to market? I'd just like to compare.
Dude I know.
The top link is pretty much just like the one in this picture except with big burly large diameter hardware instead of pinner little bolts,........ and the bottom one is like the lower chainstay up through the yolk, except with one more pivot (again with big burly large diameter hardware) and a vertical support between the chainstay and seatstay whereas this one in the pic has none.
hee hee
When there's a majorly profitable market for high end DH frames you'll see a design out of me.
well thats not nice of you at all! Clearly you have all the answers to building the ultimate DH bike of all time, and yet you hold it back for something as trivial as money??
Won't somebody please think of the children.
What I mean is, put up or shut up.
Won't somebody please think of the children.
What I mean is, put up or shut up.
Must spread rep!
Rep? whats that?
Just send people to my damn site.
Just send people to my damn site.
Then try linking to it so lazy folk don't have to copy&paste!:biggrin:Rep? whats that?
Just send people to my damn site.
An real engineer with time on his hands and the proper tools will come up with something sound. There aren't many of those in the bike industry however. Because (guess what!) it doesn't pay out.
Specialized has the best paid and best equipped engineers in the industry, so their bikes are generally the most sound. Their ergonomics are just kinda quirky.
Any idea what the shear limit is of a M10 bolt? Or the tension required to undo precision ground threads at the proper torque? How about for an M4? How much load do you think is put on that bolt being translated into a bending moment? Collect those figures and I think you'll see that for torsional loads any high quality bolt will provide the proper tightness for a secondary pivot, which is all it is there for. Bolt size is irrelevant except for contact width on the inner race of a bearing if it is actually in contact.
Now pivot SPACING is what comes into play (specifically spacing between upper and lower)...and the distribution/equalizing of twisting loads and torsion. Sundays were stiff for this reason. So are Karpiels, Canfields, Glory's, V10's/M3's. With a single pivot, the width (stance) of the pivot and the contact diameter of the bearing is what will make it stiff.
Grab a hockey stick or something, hold it up in front of you with your hands wide and elbows locked, and have someone try to twist it out of your hands, then put your hands 6" apart and have them do it again. Big difference.
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W00t! You tellin' us it's wrong to fall in love with smurfette?Wow, from a rendering?
because david turner hasn't exactly made a name for himself by copying and being a lemming
Damn... this means my recently purchased 08 DHR is worth like what? 10c? Awesome.
Joking aside, it's gonna be a hell of an interested 2009. Especially with what some of the industry folk let slip after a few drinks at Stromlo
Joking aside, it's gonna be a hell of an interested 2009. Especially with what some of the industry folk let slip after a few drinks at Stromlo
Dude, you just forfeited your right to comment on anything engineering or design related for the rest of your life.
On a more generic note about questions regarding geometry and suspension performance, Dave designed the Sunday years ago. I suspect he learned some things since then. He's smart like that.
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Not really. If they're designed and tempered right they shouldn't be flexing a bit, at least nowhere in the same order of magnitude as a rotating/sliding interface. Sometimes they do though in a poor/weak design. Other times from fatigue.
Dude, links are not tempered, at least if we are talking about the aluminum control links which I hope you are. They are machined from either the cast or forged billets. So the only design parameter to take into account vs. a cast billet is that with forged you can modify grain structure for increase strength via such things as hoop stress.
I'm with Ohio, booooo
I don't think ANY of those words mean what you think they mean....
Damn dude, did you go to a tech school?!?!
PS - I love Dave Turner. Can't really say I'm excited about all this, as I've always loved the feel of my 2 Horst link Turners over DW link bikes (for XC/trail anyway), but I'd be interested to see how the new DHR rides.